This invention relates generally to anti-weathering of storage systems for volatile multi-component fluid mixture which tend to “weather” in storage. More specifically, it concerns improvements in anti-weathering storage system for liquified material gas, referred to herein as LNG.
Weathering refers to the enrichment of the liquid state with the components with higher temperature boiling points and enrichment of the vapor state with the components with lower temperature boiling points. In the case of LNG the fluids with the higher boiling point temperatures include Propane, Butane, Ethane, and Ethylene. The primary lower boiling point fluid is Methane. Then as vapor venting occurs in a normal storage system to “boil off” the remaining liquid becomes increasingly “rich” in the components with the higher temperature boiling point, sometimes referred to as “heavies”. Typical LNG compositions range from 80 to 95 percent Methane.
In the case of LNG storage for engine fuel and other applications where it is desirable, and often necessary, to maintain a nearly constant BTU value, or Cetane value for engines, it is a problem to have varying liquid compositions because the BTU and Cetane values also vary which can damage the engine and/or degrade engine performance or cause erratic or dangerous conditions in other fuel burning appliances.
There is need for improvements in anti-weathering systems which obviate the above difficulties and problems.